Louisville coach Rick Pitino, whom Williams had committed to play for, sent the film, and from it, Williams said, he learned how to play on the elbow (near the free throw line) where Pierce has made his living for years. He also learned how to come off screens and learned footwork.

When Williams reached the NBA, he told Pierce each time they played that he had watched film of the Celtics forward. Now, after Williams formally signed a 10-day contract with the Celtics Wednesday, the two are teammates, at least for now.

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But the way the 25-year-old has played in two games thus far for the Celtics — averaging 5.5 points, 3 rebounds, and 3 assists in 18.5 minutes — he is making a strong case to stay a Celtic beyond March 1 when his contract is up.

Williams has shown that he’s more than capable playing the point guard position, even though he’s oversized for that spot at 6 feet 6 inches and 220 pounds. When asked where his playmaking skills come from, he said, “You’ve got to ask God. He gave it to me.”

In the Celtics’ 113-88 steamrolling of the Suns on Friday, Williams had four assists and made several uncannily well-placed passes that, for a moment, made it seemed as if Rajon Rondo were still on the court.

With 59 seconds left in the first quarter, Williams snagged a rebound, ran upcourt, drove to the right elbow and looked inside. When he looked there, the Suns defense quickly shrunk toward the middle, and then Williams kicked it to Jeff Green near the left wing.

And Green buried a wide-open 3-pointer.

On the next possession, Williams again grabbed the rebound, raced up the court, and noticed that Chris Wilcox had a few steps on his defender. After passing half court, Williams threaded a pass between defenders to a wide-open Wilcox, hitting him in stride for an easy, one-handed slam dunk.

That Williams could play the point guard position is something the Celtics learned last summer when he spent two weeks working out for them.

“He’s more of a point guard than anything else,” said coach Doc Rivers, who added that Williams can play the small forward and shooting guard positions as well.

In college, Williams said, he was listed as a small forward but he brought the ball up the court more often than not. And during his brief time in the NBA (he has played for the Nets, Rockets, and Kings), he also played point guard.

“I just like to have the ball in my hands,” he said.

Though his time with the Celtics has been brief, the team’s offensive rating (points per 100 possessions) is an astronomical 121.5 when he’s on the court and 102.5 when he’s not.

Williams believes he is acclimating quickly because he hasn’t been away from the NBA that long — he played for Sacramento a season ago — and because the Celtics are loaded with shooters. Playing in China this year also humbled him.

“I’ve always wanted to play basketball in the NBA,” he said, “and I’m finally getting a chance.”